Study On Synthsis Of Zeolites From Coal Fly Ash And Its Adsorption Performance Of The Water

Coal fly ash is a solid waste produced by coal-fired power plant power generation after combustion.The amount of coal fly ash have been increasing with the rising of the people demand for electricity.Despite some coal fly ash used in chemical industry,agriculture,construction and other industries,but relative to the amount of fly ash is a drop in the ocean,so the problem of comprehensive utilization of fly ash in urgent need to solve.Zeolites NaA and NaX are the most important synthetic zeolites and have been used extensively.It caused the high cost because most people used chemicals to synthesis the zeolites.In this paper,zeolites NaA and NaX were synthesized by the coal fly ash(CFA)without pretreatment,with the tablet compressing of alkali fusion method under relatively mild conditions.The tablet compressing of alkali fusion activation and CFA therewith hydrothermal reaction synthesis provides a successful method to synthesize zeolites NaA and NaX from this CFA.The alkali fusion temperature,Na2CO3/CFA mass ratio and SiO2/ Al2O3 are the most crucial parameters for the zeolite synthesis.The optimum reactant molar ratio,hydrothermal reaction temperature,and time for the zeolite NaA are as follows: 1.3Na2O: 0.6Al2O3: 1SiO2: 38H2 O at 80°C for 8h.And zeolite NaX is achieved under the optimized experimental conditions of 2.2Na2O: 0.2Al2O3: 1SiO2: 88H2 O at 100°C for 8h.The synthesized zeolites NaA and NaX were further characterized by SEM,BET,FT-IR,and TGA.The results indicate that the inexpensive raw material can be utilized to synthesize highly-crystallized zeolites NaA and NaX under optimized experimental conditions.With the new tablet alkali fusion method we can successfully synthesis the NaA and NaX zeolites.And investigated its static saturated adsorption amount of water.By changing the ratio of sodium and water ratio type can make the NaA zeolite water static saturated adsorption amount to 25.67%.Through the determination of sodium than under the condition of different water type NaA zeolite water static saturated adsorption amount proportional relationship with the diffraction peak intensity.The same results for the NaX zeolite.So the diffraction peak can be used to estimate its water absorption performance.It can greatly reduce the measuring water past static saturated adsorption amount of workload,so it's improved the efficiency of product synthesis.